This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The in vitro Pharmacology Core has assays for GTP[unreadable]S and CB1 cannabinoid receptors and is working on the development of assays for mu, delta and kappa opioid receptors. Also in development are assays for CB2, and OFQ receptors and Ca2+ signaling. Additional receptor, ion channel, and transporter binding assays are in the planning stage. This cores functions involve the use of state of the art technologies as well as time-tested laboratory methodologies. Using multi-label reader technologies and radioactive binding techniques, the core is set up to rapidly assess specific activities of compounds and extracts held in the repositories (Sourcing, Acquisition and Database Core) at the University of Mississippi National Center for Natural Products Research and of compounds synthesized by the Chemistry Core. These studies can be performed on tissues harvested from animals or from cultured cells. Mechanistic studies into the actions of extracts and their compounds can be assessed using biochemical kinetic analyses as well as cellular electrophysiology and imaging techniques, which will be added in the 3rd year. This exploratory ability is accomplished through the cores four functional components;cell culture facility, functional testing facility, biochemistry, receptor pharmacology and histology facility, and the soon to be added electrophysiology and imaging facility.